Described in Australian Patent 675376US is a plough assembly that includes a plough shank to the lower end of which there is fixed a digging blade. Behind the shank and blade is a closing tool that forms a seed bed upon which seed is deposited. Soil is moved to cover the seed by a press wheel. This assembly is a development of the assembly described in Australian Patent 541415.
Previously known ploughs have suffered from the disadvantage of not accurately locating the seed relative to the soil surface and not having provided the most efficient distribution of fertilizer to be used by seed deposited in the soil layer.